An American tourist had the experience of a life-time while on a gorilla-watching tour in Uganda.The man, known only as John, had a close encounter with a group of wild mountain gorillas near the Bwindi National Park.In a video detailing the experience he can be seen cowering while a family of apes crowds around him.

Feel for it: One of the babies is so curious it decides to climb up a nearby tree to get a better look

John laughs nervously and manages only to say his 'heart is racing'.A voice from behind the camera explains it could be his black T-shirt which is fooling the primates into thinking he is one of them.One of the babies can be seen fondling John's hair and appears as though he is trying to groom him.Moments later one of the females comes into view and begins to lick his ear before the baby climbs up a tree to get a better view of his head.

Gimme a kiss: The female comes up to John and licks his hear

All this is happening while the most dangerous and territorial of the group - the silverback - watches.He later decides he has had enough and urges the rest of the family to follow him.The males weigh about 400lbs (180kgs) and are double the size of females, with the average male eating up to 50 pounds of food a day.

Enough: The silverback decides that it is time to go and nudges the youngster before they all head off

They get their name from the large saddle-shaped patch of silver hair on their backs and fully mature after 12 years.The apes are mostly gentle giants but if threatened, the males can become quite aggressive.They are the largest of the primate species and are usually rather shy and tend stay away from humans. Park rangers said that interactions such as these are extremely rare.